HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lu, A. Y. Articles by Levin, W. Search for Related Content PubMed PubMed Citation Articles by Lu, A. Y. Articles by Levin, W. Social Bookmarking                      What's this?

JBC, Vol. 252, Issue 11, 3715-3723, Jun, 1977

Liver microsomal epoxide hydrase

A. Y. Lu, D. M. Jerina and W. Levin

1. The substrate specificity of membrane-bound and purified epoxide hydrase from rat liver microsomes has been studied. Both enzyme preparations catalyzed the hydration of a variety of alkene oxidase as well as arene oxides of several polycyclic aromatic hydrocarbons. 2. Unlike the membrane-bound enzyme, the rate of hydration for most of the substrates catalyzed by the purified epoxide hydrase was constant for only 1 or 2 min. The addition of dilauroyl phosphatidylcholine or heated microsomes to the incubation mixture extended the linearity of the reaction. 3. When rat liver microsomes were used as the source of the enzyme, the apparent Km values for many of the substrates were dependent on the amount of microsomes used. When purified epoxide hydrase was used as the enzyme source and benzo(a)pyrene 11,12-oxide as substrate, the apparent Km for benzo(a)pyrene 11,12-oxide was independent of enzyme concentration but dependent on added lipid concentration. Thus, in the absence of added dilauroyl phosphatidylcholine or in the presence of this lipid at a concentration below its critical micelle concentration, the observed Km for benzo(a)pyrene 11,12-oxide remained constant. However, when the lipid concentration was greater than the critical micelle concentration, the apparent Km value increased linearly with lipid concentration. These results are consistent with a model based on the partition of lipid-soluble substrate between the lipid micelle and the aqueous medium.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. Y. H. Lu The 1996 Bernard B. Brodie Lecture. A Journey in Cytochrome P450 and Drug Metabolism Research Drug Metab. Dispos., December 1, 1998; 26(12): 1168 - 1173. [Full Text]

				H. Glatt, C. Cooper, P. Grover, P Sims, P Bentley, M Merdes, F Waechter, K Vogel, T. Guenthner, and F Oesch Inactivation of a diol epoxide by dihydrodiol dehydrogenase but not by two epoxide hydrolases Science, March 19, 1982; 215(4539): 1507 - 1509. [Abstract] [PDF]